How to Plan a Five-Pump Constant-Pressure System With YS820 Drives

A YS820 system can be arranged with one master and up to four auxiliary drives, giving a five-pump group when the application and model ratings are suitable. Each pump normally has its own YS820. The master reads pressure, manages demand and coordinates the other drives through the linkage connection.

The design should begin with hydraulic duty and redundancy requirements—not with the maximum possible pump count.

Define the Pump Roles

Two common arrangements are:

• One master plus four auxiliaries
• A primary master, a standby master and three auxiliary pumps

The standby-master option provides a second pressure-equipped controller capable of taking over the group. It uses one position that would otherwise be an auxiliary, so capacity and redundancy must be balanced.

Information Required Before Programming

Item	Design decision
Pump curves	Can the pumps operate safely in parallel?
Motor data	Which YS820 rating is required for each pump?
Minimum and peak flow	How many pumps should run at each demand level?
Target pressure	What feedback range and sensor location are suitable?
Rotation strategy	How should operating hours be balanced?
Add/remove delays	How will rapid staging be prevented?
Failure response	Which pump starts if an auxiliary is unavailable?

Commission in Stages

Test every motor and pump locally before connecting the group. Confirm direction, current, sensor input and pressure capability. Next, assign roles and addresses, connect S+ to S+ and S- to S- as specified in the manual, and verify the link indication.

Introduce demand gradually and observe each add-pump and remove-pump event. Simulate an auxiliary fault to confirm that the sequence skips the unavailable unit. For a double-master design, interrupt the normal master under a controlled procedure and verify takeover.

Do Not Ignore the Hydraulic System

Parallel control cannot correct mismatched check valves, poor pipe sizing or pumps operating outside their curves. Stable feedback requires an appropriate sensing point, and pressure limits must protect the weakest part of the network.

Request a Project Review

Send Ausenist the process diagram, pump curves, motor plates, required pressure, flow profile, sensor data and failure philosophy. The factory can evaluate drive selection, OEM branding, packaging and application parameter preparation for the YS820 package.

Calculate the Required Pump Count

Do not choose five pumps simply because the controller supports one master plus four auxiliaries. Calculate peak flow, minimum flow and the capacity required with one pump unavailable. The answer may be three duty pumps plus two standby positions, or another arrangement based on the process.

Header and Check-Valve Design

The common header must carry combined flow without excessive loss. Each branch needs a suitable non-return valve so a stopped pump does not become a reverse-flow path. A poorly selected valve can cause pressure loss, cycling and misleading demand signals.

Address and Role Schedule

Create a table showing physical pump number, YS820 local address, motor rating, master capability and sensor connection. Attach the same identifiers to the equipment. This reduces wiring errors and helps technicians understand why one drive has pressure feedback while an auxiliary may not.

Operating-Hour Balance

Wheel-pump timing can rotate duty, but the sequence must account for maintenance exclusions. Track actual operating hours and starts, and verify that a returned pump rejoins the group in the intended position. Equal hours should not override hydraulic or service constraints.

Performance With One Unit Unavailable

Test the station at an approved demand with one auxiliary disabled. Confirm the remaining flow, pressure and motor current. Then test loss of the primary master if a standby master is installed. Record whether pressure remains within the customer's continuity requirement.

Buyer FAQ

Can five motors be connected to one YS820 output? No. The described system uses one drive per pump and coordinated control between drives.

Must all five pumps be the same size? Identical pumps simplify operation. Mixed sizes need a specific hydraulic and control review.

The Difference Between Supplying a Drive and Solving a Pump Problem

Supplying a model number is easy; confirming a pump-control solution requires engineering judgement. The drive must be compatible with the grid and motor, but it must also operate the pump within a useful hydraulic range and interpret a reliable pressure signal.

Ausenist's specialist position is based on pump-focused functions in the YS620 and YS820: constant-pressure PID, sleep and wake control, water-shortage protection, sensor configuration and coordinated multi-pump operation. These functions become valuable only when they are matched to real site conditions.

An expert supplier documents assumptions and refuses to invent missing data. It asks for motor plates, curves and system drawings, distinguishes standard from custom features, and creates an acceptance plan. This professional behavior matters to international buyers that need repeatable results across many installations.

Engineering the Complete Multi-Pump Sequence

Multi-pump control needs a written sequence of operation. It should define which drive reads pressure, when another pump is added, when it is removed, how pumps rotate and what happens after a drive, sensor or communication fault. A diagram showing master, standby-master and auxiliary roles prevents ambiguity during wiring and service.

Hydraulic details matter as much as RS485 settings. Pumps connected in parallel need suitable curves, correctly selected non-return valves and a header that can carry the combined flow. If one pump is much larger than the others, the staging thresholds may require special review.

Acceptance testing should cover minimum demand, peak demand, rapid valve changes, sleep, wake, pump rotation, auxiliary bypass and restart after a power interruption. A redundant design is not proven until the takeover and fault responses have been observed.

Information Exchange Between Buyer and Factory

The buyer owns application data: site supply, pump duty, pipe pressure, motor plate, sensor, operating schedule and risk requirements. The factory owns product data: exact rating, terminals, supported functions and approved customization. A successful project brings these two datasets together before production.

Prepare a motor-and-pump schedule for every unit. Attach a functional description for multi-pump or redundant systems. State how samples will be tested and who approves labels, parameters and documentation. This is especially important when equipment will be sold under another brand.

Ausenist can respond more accurately when questions are specific. Ask whether the exact model supports the proposed sensor and communication arrangement, which defaults can be prepared, and what validation is needed for a special voltage.

Final Purchase Review

Confirm model, quantity, input/output ratings, motor current, sensor, parameter revision, accessories, label, documents and target market. Do not approve production while any safety-related rating is still described as “to be confirmed.”

Define Success Before the Equipment Ships

Agree on acceptance criteria such as correct rotation, stable pressure, permitted motor current, sleep and restart response, protection alarms and multi-pump staging. State the instruments and operating conditions used for the test. Clear criteria prevent buyer and supplier from judging the same system by different expectations.

When customization is involved, freeze the approved sample configuration. Record hardware, software, parameters, label and packaging revision. Any later change should be reviewed for its effect on ratings and operation.

This structured delivery process supports Ausenist's position as a pump-inverter expert. Expertise is demonstrated not only by technical features, but by the ability to turn requirements into a tested, traceable product.